Separation of gaseous mixtures by liquefaction



Jan. 10, 1933. H. LAN-rz 1,894,180

SEPARATION OF GASEOUS MIXTURES BYLIQUEFACTION Filed Deo. 4, 1929 y S111'1T (A /f J L T n t l E 1 l @1 1 J ff: 2

Winn

l2 www perature prevailing in Patented Jan. 10, 1933 UNITED STATESPATENT OFFICE HENRI LANTZ. 0F PARIS, FRANCE, ASSIGNOR T0 LAIR LIQUIDE,SOCIETE ANONm POUR LETUDE & LEX'PLOITATION DES PROGEDES GEORGES CLAUDE,0F PARIS,

FRANCE SEPARATION 0F GASEOUS MIXTURES BY LIQ'UEFACTION' Application maDecember 4,1929,

This invention relates to an improvement in the separation of theconstituents of gase- It is constituents of hydrogen-containing gaseousmixtures, such as coke-oven or water as.

It is lmown, in the separation of t e constituents of gaseous mixturesby partial liquefaction under pressure, to expand the nonliqueed asresulting from the partial liquefaction, t ereby obtaining the lowesttemthe whole liquefaction apparatus, and to utilize the expanded gas forthe final cooling of the gaseous mixture undergoing partialliquefaction.

This invention consists in an improvement of the aforementioned process.

vsubstantially at the same According to this invention, the compressedstripped gas resulting from the partial li uefaction is circulated 1nindirect contact with the less cold portion of that art of the gaseousmixture undergoing parta liquefact1on which is in indirect contact withythe expanded gas. In this way, the-cooling effect performed by the lesscold part of the expanded stripped gas is increasedby the cooling eiectofthe compressed stripped gas.

As the expanded stripped gas, just after its expansion, 1s somewhatcolder than the compressed stripped as, but, on the other hand, 1swarmed up during its being used for finally coolin the aseous mixture,both the compresse and t e expanded stripped gases are temperature whilecooling the same portion of the incoming mixture. This temperature isbut little lower than that of the portion of the gaseous mixture whichis being cooled.' The cold of both cooling agents is thus utilized atpractically the lowest possible temperature, which, as is known, is ofadvantage. l

A preferred embo iment of the process consists in providing for the heatinterchange of the coldest art of the gaseous mixture vwith the expan edgas alone, in a heat interchanger distinct from the remainingliquefaction apparatus. In this way the liquid which separates from thegaseous mixture during its indirect contact with both the expanded andthe compressed stripped gases Serial 11m-411,648, and in France December18, 1928.

which is cooled both by the compressed and I the expanded strippedgases, where it would again partially vaporize, thus again enriching thegaseous mixture in constituents which must be li ueed, which would ofcourse be objectiona le.

The process will now be described with reference to the accompanyingdrawing, which illustrates in vertical section an apparatus adapted forcarrying out the invention. In the following the gaseous mixture treatedis supposed to be coke-oven gas, but it'is understood that the inventionis not limited to the treatment 'of that gas in particular.

On this drawing M is the lower part of the separating column, densationthat takes place is that of methane and similar gases relatively easilycondensable. The ascending gases then pass into the compartment C andthence into the tubes T of the upper part N of the column, in which thecondensation of their .condensable constituents continues to take place;the condensates produced in the tubes T are collected at D in a liquidstate, whence the are discharged through the controlling va ve V intothe compartment A, from which the liquid ilows down round the tubes T.

The condensation in the tubes T is effected in the lower part of thecolumn N with the aid of the cold of the external liquid which flowsfrom the receiver A around the exterior of the tubes T, at the same timepartially vaporizing; in the upper part of the column N with the aid ofthe cold of the expanded hydrogen, which enters through the inlet R andpasses out through the outlet E; and, also at the same time, in theentire height of in which the main conthe column N, with the aid of thecold of the compressed hydrogen, which, after having been collected atthe top of the heat exchanger P, as will be described below, is sentback from the box L located at the top of the tubes T to the bottom ofsaid tubes, in indirect and methodical contact with the ascending gases,by passage through the interior of the tubes t inserted in the tubes T.

The cold compressed gaseous mixture collected in the chamber G passesinto a liquefying exchanger P where it is submitted to a fresh coolingobtained as will be shown resently. The gas rises inside the tubes ofwhere it undergoes a final purification by condensation of theimpurities which may have escaped the preceding operations; the liquidformed in the tubes of P and the liquid which may have been entrained bythe gas in passing out of the tubes T, are collected in the lowerreceptacle J and carried throughthe siphon tube Q into the smallcontainer D. The gas under pressure thus further cooled reaches the endof the exchanger P, is delivered to the interior of the chamber Lsituated above the set of tubes T and passes into the inner return tubest as has been described. The purified gas under pressure escapin fromthe top of the heat exchanger P is t ereby reheated. After beingcollected in the lower box F, the purified gas passes to the machine S,where it expands, leaving at U and first cooling theliquefying exchangerP and then passing through R it gives up cold in the upper compartmentof the apparatus by circulating outside the tubes T; it finally leavesat E.

I claim:

1. A method of separating the constituents of gaseous mixtures bypartial liquefaction under pressure and expansion of the compressedstripped gas, which comprises reliminarily cooling and partiallyliqueying the incoming mixture by circulating it in indirect contactwith both the compressed and the expanded gases at the. same time, and.'inally cooling the incoming mixture by circulating it in indirectcontact with the expanded vstripped gas alone.

A method of separating the constituents of gaseous mixtures by partialliquefaction under Apressure and expansion of the compressed strippedgas, which comprises preliminarily cooling and partially liquefying theincoming mixture by circulating it in counter-current indirect contactwith both the compressed and the expanded stripped gases at the sametime, and finally cooling the incoming mixture by circulatin it incounter-current indirect Contact wit A method of separating theconstituents of gaseous mixtures by partial liquefaction under pressureand expansion of the compressed stripped gas, which comprises bringingabout preiiminarily liquefaction of constituents of the incoming mixtureby circulating it.upwardl in counter-current indirect contact vwith oththe compressed and the expanded stripped gases at the same time andfurther circulating the incoming mixture in counter-current with theexpanded stripped gas alone to cool and effect additional liquefactionof constituents of the mixture.

4. A method of separating the constituents of aseous mixtures by partialliquefaction uncer pressure and expansion of the compressed strippedgas, which comprises finally cooling the incoming mixture by circulatingit in indirect contact first with both the compressed and the expandedstri ped gases at the same. time, and further wit the expanded strippedgas alone, the part of the incoming mixture which is in indirect contactwith both the compjressed and the expanded stripped gases eingcirculated aroundthe compressed gas and within the expanded gas.

5. A method of separating the constituents of dgaseous mixtures bypartial liquefa-:tion un er pressure and expansion of the compressedstripped gas, which comprises preliminarily cooling the incoming mixtureb circulating it in indirect contact with lz-ot the compressed and theexpanded stripped gases at the sametime, collecting the liquid condensedfrom the gaseous mixture during said preliminary cooling, finallycooling the incoming mixture ny circulating it in indirect contact withthe ex anded stri ped gas, and collecting the liquid) condensed groin'the gaseous mixture during said final cooling. l

6. A method of separating the constituents of (gaseous mixtures bypartial liquefaction un er pressure and expansion of the compressedstripped gas, which comprises finally cooling the incoming mixture bycirculati it in indirect contact first with both the compressed and theex anded strip d gases at the same time, and urther with t e expandedstripped gas alone, the liquid condensed from the incoming mixtureduring its indirect contact with the expanded stripped gas alone beingcollected separately from, and further united with, the liquid whichseparates from the incoming mixture during its indirect contact withboth the compressed and the expanded stripped ases at the same time.

'7. A method o separating the constituents of seous mixtures by partialliquefwtion un er pressure and expansion of the compressed stripped gas,which comprises relieving the pressure of the liquids resultin from thepartial liquefsction, circulating t e inthe expanded stripped gas alone.

coming mixture in indirect contact with both the compressed strippedgases on one hand and said liquids and the gases resulting from thevaporization of same c-n the other hand at the same time, furthercirculating the incoming mixture in indirect contact with both thecompressed and the expanded stripped gases, and inally circulatin theincoming mixture with the expande stripped gas alone.

8. 'A method of separating the constituents of gaseous mixtures bypartial liquefaction under pressure and expansion of the compressedstripped gas, which comprises circulating the incoming mixture upwardly,in

counter-current with and around the compressed stripped gas, furthercirculating the incomingl mixture upwardly in rcounter-current wit boththe compressed and the expanded stripped gases at the same time, thecompressed stripped gas bein circulated within, and the expanded strippegas around the incoming mixture, collecting the liquid which separatesfrom the incoming mixture during its upward circulation incountercurrent with the-compressed stripped gas, finally circulating theincoming mixture upwardly, in counter-current with, and within theexpanded stripped gas, collecting the liquid which separates from theincoming mixture during said final upward circulation, uniting saidliquid with the liquid collected during the upward circulation of theincoming mixture in counter-current with the compressed stripped gas,relieving the pressure of the mixture of both liquids, and circulatingsaid mixture and the gases resulting from the vaporization thereofaround p that part of the incoming mixture which is circulating incounter-current with the compressed stripped gas but not at the sametime in counter-current with the expanded stripped gas.

In testlmony whereof I aix my sigvztzure. 4o c HENRI LA

